public class MainApp {
	public static void main(String[] args) {
		Rectangle a = new Rectangle();
		System.out.println(a.getLength());
		System.out.println(a.getWidth());
		System.out.println(a.mianJi());
		System.out.println(a.zhouChang());
		Rectangle b = new Rectangle(3, 5);
		System.out.println(b.getLength());
		System.out.println(b.getWidth());
		System.out.println(b.mianJi());
		System.out.println(b.zhouChang());
		b.setWidth(-3);
		System.out.println(b.getWidth());
		System.out.println(b.mianJi());
		System.out.println(b.zhouChang());
	}
}
